Door lock



June 26, 1928.

1,675,041 T. NAKAHARA DOOR LOCK Filed June S, 1926 2 sheets-sheet '1 June 26, 1928.

T. NAKAHARA 4Filed. June 5, 1926 Doon LOCK 2 Sheets-Sheet 2 Patented June" 26, 1928.

UNITED STATES TOICHI NAKAHARA, OF lSHIMIOSHIBUYA, NEAR TORY,v JAPAN.

noon Loox.

Application med June 5,

This invention relates to a door lock vof the type having a spring pressed latch actuated by a,handle, and a locking bolt actuated by a key. The object of the invention is to provide a door lock of which key hole is normally closed by a shutter, and said shutter is held in closed position by a means actuated from inside of the door or by a letter disc on the outer plate., so that the shutter can not be opened by any unauthorized person even though he has the corresponding key.

Anothervobject of the invention is to pre.

vent the movement of the spring pressedv latch when the locking bolt is in locking position by a simple means.

The invention possesses many other advantageous features, some of which, with the foregoing, will be set forth'at length in theI following description, where I shall outline in full that form of the invention which I have selected for illustration in the drawings accompanying and forming part of the 1 .present specification.

Referring to the drawings:

Figure 1 is a front elevationof the lock according to this invention fitted to the door;

Fig. 2 is a view showing the inner plate;

Fig. 3 shows the insidesurface of the outer plate shown in Fig. 1;

Fig. 4 shows the inside surface of the in- `ner plate shown in Fig. 2;

Fig. 5 is a sectional side view of the lock:

Fig. 6 shows the parts in the embedded casing;

Fig. 7 is a similar view but showing the position of the parts when the locking bolt and latch are projected;

Figs. 8 and 9 are plan and end views of the key for opening the lock;

Fig. 10 is a front view of a modified form of the outer plate; i 4

Fig. 11 shows the inside surface of said I outer plate.

In the drawings,'1 isa part of the door to which the lock is fitted. The lock consists n of a casing 2 to be embedded in the frame of the door, an outer plate 3 mounted on 'the outside of the' door, and an Inner plate 4 mounted on the inner side of the door. 6 is a latch which is normally pressed outward- 1926. Serial No. 113,893.

also provided with two notches 23 which are.

adapted to be engaged ,by the wards 10 of the key 9. Rocking members 24 and 25 are pivotally mounted at 26 to the casing 2, and each is provided at its outer end with a tooth 27 and is pressed inwardly to each other by means of springs 28.v Each rocking member consists of a plurality of superposed thin plates. Secured to the under side of the bolt 8 is an arm 29 which is adapted to engage With a shoulder formed on the latch 6, so as to retain the latter lin its projected position as far as the bolt 8 is in the locking position.

The latch 6 carries, at the inner end, the

- projections 30 which are normally engaged by the arms 31 secured on kthe spindle of the handle 7. v

vThe inner plate 4 supports the stud of the handle 32, which stud has a gear 33 meshing with a pinion 34 on the square spindle 35 which is supported in the bearing 36 in the plate 4. Near the outer end, the spindle 35 carries a key head 37 and an actuating member having a projection 44. The square spindle 35 and the pin 14 for receiving the key 9 are'arranged symmetrically with respectto lthe axis of the locking bolt 8. The size and shape of the key head 37 is similar tov those of the head -of 'the key 9. Each of the spring pressed rocking arms 24 and 25 .is adapted to be engagedby the key head 37 and by the head of the key 9, and said rocking arm is arranged in such a manner that it may be actuated Veither by the key head 37 or by the head of the key 9. y

As shown in Figures 8 and 9, the key 9 is provlided with the wards 10 on each side, and its extremity 11 is shaped as a wedge. A central bore 12' is provided for engaging with the pin 14. v

13 is a Window providedv in the outer plate 3 through which the key 9 is inserted. (Figs. 1 and 5.) lThis window 13 is normally closed by shutters 15 and 16, the shutter 15 being stationary whilst the shutter 16 being adapted to slide between the plate 3 and the supporting plate 17. The sliding shutter 16 is pressed downwardly by the spring y18, thus it is normally closed. The inner edges ofthe shutters y15 and 16 arev beveled so. as to form a horizontal groove 20 having a V-shaped cross section. Thus, it will be seen that the shutter -16 may be opened by inserting the Wedge shaped head- 12 of the key 9. A vertical groove line 21 is provided in both shutters, which groove Abeing not .completely cut and is not intended for actual use, but for the purpose of merely causing a confusion.

On the inner side of the outer plate 31s mounted a retaining plate 41 which is slidably mounted by ymeans of slots 42 and pms 43. At the lower part, the retaining plate 41 is provided with a notch 45 adapted to be engaged by the projection member 44 on 'the spindle 35, and on the opposite edge with another notch 49 which is adapted to be en aged by a projection 48 carried by the p ate 47. The plate 47 lies beneath theretaining plate 41 and is connected with a spring 46. When the spindle 3 5 1s rotated by manipulating the handle 32 from inside of the door, the projection member 44 will come into engagement with the notch 45 pressing the plate 47 rightwardly in Fig. 3, thereby the plate 41 will be raised or lowered. Then, the plate 41 will be retained in its raised or lowered position by means of the projection 48 on the plate' 47, which projection 48 resiliently engaging with either one of the two notches 49. The side extension 50 of the retaining plate 41 is adapted to engage and retain the projection 51 which is fixed -to the rear face of the sliding shutter 16. Thus, it will be seen that the sliding shutter 16 is normally held in closed position by the retaining plate 41 and that it may be released by manipulating the handle 32. Y

As shown in Figure 3, a key hole 19 is formed on the plate 17, through which hole the key 9 is inserted in the casing opening the shutter 16 by its wedge'shaped end and the key is brought into engagement with the pin 14. i,

In the modiiiication shown in Figures 1() and 11, a letter/disc 22 is rotatably mounted on the outer plate 3. 23 is the spindle on the disc, and-24 is a knob for rotating the disc 22.

At the inner end of the spindle 23 is fixed a disc 26 having a notch 25. The sliding shutter 16 has a projection 31 on the rear side, which projection is projected through the aperture 32. formed in,V the plate 17, and is normally engaged by the periphery of the disc 26, thereby the shutter 16 is normally held closed. When, however, the notch 25 in the disc 26 comes in register with the projection 31, the latter may engage with Y the former upon the key 9 being inserted persons to know what kind of key may' fit i between the shutters 15 and 16, thus allowing the 4shutter 16 to be yieldingly opened by the key 9.

According to this invention, the key window 13 is normally closed by the shutters so that' it is impossible for unauthorized for the lock. YVhe-n the .locking bolt 8 is in locking position, the spring pressed latch 6 will be also held firmly in its projected position. The rocking men'ibers 24 and 25 are composed of a group of thin plates. and by using the different combinations of said group the wards oi the key 9 may be formed in many different shapes.

What I claim is:-

1. A doml lock having a handle. a spring i'essed latch actuated by the handle,` a ock'ing bolt adapted to be actuated by a key, a key window in the outer plate, a sliding shutter normally closing said window and adapted to be opened by the insertion of the key, a projection fixed tothe said sliding shutter, a letter disc,.a retaining disc connected to the letter' disc and having a notch which comes in register with the projection on the shutter when the 'said letter disc is in the predetermined angular position, allowing thereby the shutter to be opened by the insertion of the key.

2. A door lock according to claim 1,.

wherein a key window is normally closed by stationary and sliding shutters, each having a beveled abutting edge so as to form a V-shaped groove, into vwhich a wedge shapedend of the key is adapted to be inserted for opening the shutter.

3. 'A door lock according 'to claim 1, wherein a means is provided for normally locking the shutter in thel closed position,

thereby preventing the insertion of the key through the keywindow, which means being adapted to be manipulated from inside of the door.

4. A door lock comprising a locking bolt adapted to be actuated by a key, and having an outer plate provided with a' key hole,

a sliding shutter normally closing. said key hole and adapted 'to be opened by the insertion of the key, said shutter havin a projection fixed thereto, a retaining isk connected to the letter disk whereon the and having a notch which comes in register with the projection on the shutter when the said letter disc is in the predetermined angular position, allowing thereby the shutter'to be opened by the insertion of the key' 5. A door lock according to claim 4, wherein the key hole is normally .closed by stationary and sliding shutters, each having a beveled abutting edge arranged to form a V shaped horizontal groove, into which a wedge shaped end of the key is adapted to be inserted for opening the shutter, and also each having Aan ineompletely cut groove for the purpose of merely causing a confusion.

'rorcrn- N'AKAHAnA.

`letter may engage with the said projection no 

